class MailManagerTest

class MailManagerTest extends UnitTestCase {

  /**
   * The cache backend to use.
   *
   * @var \Drupal\Core\Cache\CacheBackendInterface|\PHPUnit\Framework\MockObject\MockObject
   */
  protected $cache;

  /**
   * The module handler.
   *
   * @var \Drupal\Core\Extension\ModuleHandlerInterface|\PHPUnit\Framework\MockObject\MockObject
   */
  protected $moduleHandler;

  /**
   * The configuration factory.
   *
   * @var \Drupal\Core\Config\ConfigFactoryInterface|\PHPUnit\Framework\MockObject\MockObject
   */
  protected $configFactory;

  /**
   * The plugin discovery.
   *
   * @var \Drupal\Component\Plugin\Discovery\DiscoveryInterface|\PHPUnit\Framework\MockObject\MockObject
   */
  protected $discovery;

  /**
   * The renderer.
   *
   * @var \Drupal\Core\Render\RendererInterface|\PHPUnit\Framework\MockObject\MockObject
   */
  protected $renderer;

  /**
   * The mail manager under test.
   *
   * @var \Drupal\Tests\Core\Mail\TestMailManager
   */
  protected $mailManager;

  /**
   * The request stack.
   *
   * @var \Symfony\Component\HttpFoundation\RequestStack|\Prophecy\Prophecy\ProphecyInterface
   */
  protected $requestStack;

  /**
   * The current request.
   *
   * @var \Symfony\Component\HttpFoundation\Request
   */
  protected $request;

  /**
   * A list of mail plugin definitions.
   *
   * @var array
   */
  protected $definitions = [
    'php_mail' => [
      'id' => 'php_mail',
      'class' => 'Drupal\\Core\\Mail\\Plugin\\Mail\\PhpMail',
    ],
    'test_mail_collector' => [
      'id' => 'test_mail_collector',
      'class' => 'Drupal\\Core\\Mail\\Plugin\\Mail\\TestMailCollector',
    ],
  ];

  /**
   * {@inheritdoc}
   */
  protected function setUp() : void {
    parent::setUp();

    // Prepare the default constructor arguments required by MailManager.
    $this->cache = $this
      ->createMock('Drupal\\Core\\Cache\\CacheBackendInterface');
    $this->moduleHandler = $this
      ->createMock('Drupal\\Core\\Extension\\ModuleHandlerInterface');

    // Mock a Discovery object to replace AnnotationClassDiscovery.
    $this->discovery = $this
      ->createMock('Drupal\\Component\\Plugin\\Discovery\\DiscoveryInterface');
    $this->discovery
      ->expects($this
      ->any())
      ->method('getDefinitions')
      ->willReturn($this->definitions);
  }

  /**
   * Sets up the mail manager for testing.
   */
  protected function setUpMailManager($interface = []) {

    // Use the provided config for system.mail.interface settings.
    $this->configFactory = $this
      ->getConfigFactoryStub([
      'system.mail' => [
        'interface' => $interface,
        'mailer_dsn' => [
          'scheme' => 'null',
          'host' => 'null',
          'user' => NULL,
          'password' => NULL,
          'port' => NULL,
          'options' => [],
        ],
      ],
      'system.site' => [
        'mail' => 'test@example.com',
      ],
    ]);
    $logger_factory = $this
      ->createMock('\\Drupal\\Core\\Logger\\LoggerChannelFactoryInterface');
    $string_translation = $this
      ->getStringTranslationStub();
    $this->renderer = $this
      ->createMock(RendererInterface::class);

    // Construct the manager object and override its discovery.
    $this->mailManager = new TestMailManager(new \ArrayObject(), $this->cache, $this->moduleHandler, $this->configFactory, $logger_factory, $string_translation, $this->renderer);
    $this->mailManager
      ->setDiscovery($this->discovery);
    $this->request = new Request();
    $this->requestStack = $this
      ->prophesize(RequestStack::class);
    $this->requestStack
      ->getCurrentRequest()
      ->willReturn($this->request);

    // @see \Drupal\Core\Plugin\Factory\ContainerFactory::createInstance()
    $container = new ContainerBuilder();
    $container
      ->set('config.factory', $this->configFactory);
    $container
      ->set('request_stack', $this->requestStack
      ->reveal());
    \Drupal::setContainer($container);
  }

  /**
   * Tests the getInstance method.
   *
   * @covers ::getInstance
   */
  public function testGetInstance() {
    $interface = [
      'default' => 'php_mail',
      'example_testkey' => 'test_mail_collector',
    ];
    $this
      ->setUpMailManager($interface);

    // Test that an unmatched message_id returns the default plugin instance.
    $options = [
      'module' => 'foo',
      'key' => 'bar',
    ];
    $instance = $this->mailManager
      ->getInstance($options);
    $this
      ->assertInstanceOf('Drupal\\Core\\Mail\\Plugin\\Mail\\PhpMail', $instance);

    // Test that a matching message_id returns the specified plugin instance.
    $options = [
      'module' => 'example',
      'key' => 'testkey',
    ];
    $instance = $this->mailManager
      ->getInstance($options);
    $this
      ->assertInstanceOf('Drupal\\Core\\Mail\\Plugin\\Mail\\TestMailCollector', $instance);
  }

  /**
   * Tests that mails are sent in a separate render context.
   *
   * @covers ::mail
   */
  public function testMailInRenderContext() {
    $interface = [
      'default' => 'php_mail',
      'example_testkey' => 'test_mail_collector',
    ];
    $this
      ->setUpMailManager($interface);
    $this->renderer
      ->expects($this
      ->exactly(1))
      ->method('executeInRenderContext')
      ->willReturnCallback(function (RenderContext $render_context, $callback) {
      $message = $callback();
      $this
        ->assertEquals('example', $message['module']);
    });
    $this->mailManager
      ->mail('example', 'key', 'to@example.org', 'en');
  }

}